Libraries
The independent libraries that make up Barrel, and where to find each one's deep reference.
Barrel is one database made of independent Apache 2.0 libraries. You use the full
full barrel API, or depend on a single library. This page lists them and links the
deeper per-library documentation where it exists.
The stack
| Library | Role |
|---|---|
barrel | The API you use in these docs: documents, blobs, and vectors under one id. |
barrel_docdb | The document layer: version-vector MVCC, BQL, attachments, replication. |
barrel_vectordb | The vector layer: HNSW, DiskANN, FAISS, and BM25 with hybrid search. |
barrel_embed | Embedding generation across providers (OpenAI, Ollama, local, and more). |
barrel_rerank | Cross-encoder reranking. |
barrel_crypto | Encryption-at-rest primitives and key providers. |
barrel_spaces | The agent layer: spaces, capability tokens, sessions, handoffs. |
barrel_server | The REST/JSON and MCP server over the barrel API. |
barrel_faiss | Optional Erlang NIF bindings for FAISS. |
barrel-lite | The offline-first TypeScript browser client. |
Per-library documentation
Each library publishes its own reference site: the guides it ships, plus an API reference generated from the module documentation, so it cannot drift from the source.
- barrel - the full database.
- barrel_docdb - the document layer.
- barrel_vectordb - the vector layer.
- barrel_embed - embedding providers.
- barrel_server - the REST/JSON and MCP server.
- barrel_spaces - the agent layer.
- barrel_rerank - cross-encoder reranking.
- barrel_crypto - encryption at rest.
barrel_faiss links against a system FAISS build, so its reference ships on
HexDocs rather than here. Every library is on
HexDocs under its own name.
The source for every library lives in the umbrella repository at github.com/barrel-db/barrel.